With the increasing popularity of portable electronic devices (such as smart phones, tablets, and notebook computers), more attention has been directed to wireless communication technology for portable electronic devices in recent years. The quality of wireless communication depends on the efficiency of an antenna in the electronic device. Therefore, how the radiation performance (such as gain) of an antenna can be improved has become quite an important issue in the art.
Further, although some existing antenna architectures (for example, a planar inverted-F antenna (PIFA)) can generate multiple frequency bands, the space for holding an antenna in such a product has been greatly reduced in size due to the recent trend of product miniaturization. With such a reduced space, different frequency bands will affect each other, resulting in a lower matching effect for antennas.
Furthermore, although U.S. Patent Publication No. 20140320359A1 discloses a “communication device and antenna element therein,” which utilizes a first matching circuit and a second matching circuit to adjust an impedance value, the antenna therein is separately connected to a communication module, resulting in cost increase. Further, with the advent of the next generation communication technology 5G Licensed Assisted Access (LAA), the design therein does not meet the needs of the application frequency band of a fifth generation communication system.